feat(nodeadm): use cached kubelet version to reduce config time (#1991)

Author: cartermckinnon

nodeadm/cmd/nodeadm/init/init.go

@@ -2,6 +2,7 @@ package init
 
 import (
 	"context"
+	"time"
 
 	"github.com/aws/aws-sdk-go-v2/aws"
 	"github.com/aws/aws-sdk-go-v2/config"
@@ -46,6 +47,8 @@ func (c *initCmd) Flaggy() *flaggy.Subcommand {
 }
 
 func (c *initCmd) Run(log *zap.Logger, opts *cli.GlobalOptions) error {
+	start := time.Now()
+
 	log.Info("Checking user is root..")
 	root, err := cli.IsRunningAsRoot()
 	if err != nil {
@@ -139,6 +142,8 @@ func (c *initCmd) Run(log *zap.Logger, opts *cli.GlobalOptions) error {
 		}
 	}
 
+	log.Info("done!", zap.Duration("duration", time.Since(start)))
+
 	return nil
 }
 

nodeadm/internal/kubelet/version.go

@@ -1,6 +1,8 @@
 package kubelet
 
 import (
+	"errors"
+	"os"
 	"os/exec"
 	"regexp"
 )
@@ -10,17 +12,19 @@ func GetKubeletVersion() (string, error) {
 	if err != nil {
 		return "", err
 	}
-	version := parseSemVer(*rawVersion)
+	version := parseSemVer(string(rawVersion))
 	return version, nil
 }
 
-func GetKubeletVersionRaw() (*string, error) {
-	output, err := exec.Command("kubelet", "--version").Output()
-	if err != nil {
+const kubeletVersionFile = "/etc/eks/kubelet-version.txt"
+
+func GetKubeletVersionRaw() ([]byte, error) {
+	if _, err := os.Stat(kubeletVersionFile); errors.Is(err, os.ErrNotExist) {
+		return exec.Command("kubelet", "--version").Output()
+	} else if err != nil {
 		return nil, err
 	}
-	rawVersion := string(output)
-	return &rawVersion, nil
+	return os.ReadFile(kubeletVersionFile)
 }
 
 var semVerRegex = regexp.MustCompile(`v[0-9]+\.[0-9]+.[0-9]+`)

templates/al2023/provisioners/install-worker.sh

@@ -187,6 +187,9 @@ done
 
 sudo rm ./*.sha256
 
+kubelet --version > "${WORKING_DIR}/kubelet-version.txt"
+sudo mv "${WORKING_DIR}/kubelet-version.txt" /etc/eks/kubelet-version.txt
+
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